Small Enzyme-Containing Granules

ABSTRACT

The invention provides small enzyme-containing granules having an inorganic salt core and an enzyme-containing layer coated over the core, and methods for producing such granules. The majority of the enzyme granules are less than 300 μm in diameter. The granules are suitable for incorporation into compositions such as cleaning, textile processing, and animal feed compositions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/028,748, filed Feb. 14, 2008, and U.S. Provisional Application No.61/115,146, filed Nov. 17, 2008, both of which are incorporated byreference herein in their entireties.

FIELD OF THE INVENTION

The invention relates to small enzyme-containing granules produced in afluidized bed spray coater, wherein the majority of the particles have adiameter of less than 300 microns and contain a single core.

BACKGROUND

Enzyme-containing granules are incorporated into products in severalindustries, including detergent, textile-processing, food (e.g.,baking), animal feed, and fuel ethanol industries. Such granules may beprepared by a number of technologies, including fluidized bed spraycoating, high sheer granulation, extrusion, spheronization, prilling,and spray drying.

Enzyme-containing granules of a small size (e.g., less than 300 microndiameter) are desirable in certain applications because small granulesproduce less dust and better protect enzymes against deactivating agentsthan do spray dried powders, while being easier to blend morehomogeneously and inconspicuously with other powdered ingredients commonin these industries. Such powders include surfactants and otherdetergent ingredients, buffers, salts, grain flours, starches, sugars,and/or inert diluents. A smaller granule has less tendency to segregatewhen blended into such powders and fine granular materials. Further, agiven mass of smaller enzyme-containing granules will contain many moreindividual granules than the same mass of larger granules, and hencewill provide greater homogeneity (less variation in net concentration)within a sample or aliquot of the powder into which it is blended,particularly for smaller sample sizes, e.g., less than about 50 to 100grams of powder per aliquot. Granules with diameters in the range of 150to 350 microns are advantageous because they are not so small that theyproduce large amounts of dust or are vulnerable to loss in enzymepotency and they are not so large that they blend poorly with typicalpowdered products.

It would be desirable to prepare such granules in a top-spray fluid bedcoater because this technology can produce coated granules at arelatively low production cost and low equipment cost relative to itshigh productivity, i.e., mass of granules produced per unit time. Withsuch a coating process, by judicious selection of the size distributionof the core particles, a resultant narrow and defined particle sizedistribution of final coated product can be achieved, which isadvantageous for homogeneous quality and blending with powders.

A top-spray fluid bed coater is a coating vessel in which a bed ofparticles is suspended in a randomly circulating or churning bedproduced by upward flow of air through a screen or retaining plate atthe base of the vessel, and into which liquid coating solutions can bedirected via spray nozzles inserted into the bed. Top-spray fluid bedcoating is a well-established technology for producing coatedenzyme-containing granules in a larger size range, i.e., where themajority of the granules have a diameter greater than 300 microns.However, with smaller granules, there is a strong tendency for thefluidized granules to agglomerate or stick together when sprayed withenzymes and other solutions, due to the presence of binders in thecoating solutions. Agglomeration of fine powders is often employeddeliberately to produce dry products, but such agglomerated powders areoften undesirable because they typically have a broad particle sizedistribution, do not flow freely, and tend to form dusts or break downto fines when subjected to shear, impact, or other forces encountered inhandling. Furthermore, coating of agglomerates is typically inefficient,since much of the coating material is incorporated into interstitialzones, rather than evenly coating the substrate particles.

There is a need for an improved method for production of small,uniformly coated, substantially discrete enzyme-containing granules in atop-spray fluid bed coating process.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the invention provides a population of enzyme-containinggranules. At least about 95% of the granules in the population contain asingle core consisting of one or more inorganic salts, and the granulescontain an enzyme-containing layer coated over the core. In someembodiments, at least about 50%, 60%, 70%, 80%, or 90% of the granulescontain a diameter of about 150 to about 300 microns. In someembodiments, at least about 50%, 60%, 70%, 80%, or 90% of the granulescontain a diameter of about 200 microns to about 350 microns. In someembodiments, at least about 50%, 60%, 70%, 80%, or 90% of the granulescontain a diameter of about 150 to about 355 microns.

In one embodiment, the core consists of sodium sulfate. In someembodiments, at least about 80% or 90% of the cores contain a diameterof about 150 to about 250 microns. In some embodiments, at least about80% or 90% of the cores contain a diameter of about 200 to about 300microns. In some embodiments, the cores contain a bulk density greaterthan about 1.2 g/ml or 1.4 g/ml.

In some embodiments, the enzyme-containing layer contains an enzymeselected from a protease, a cellulase, an amylase, and a phytase. Insome embodiments, the enzyme-containing layer further contains at leastone of a polymer, a sugar, a starch, and a surfactant.

In some embodiments, the granules further contain a layer containing abarrier salt coated over the enzyme-containing layer. In one embodiment,the barrier salt layer contains sodium sulfate. In some embodiments, thebarrier salt layer contains a mixture of two or more salts. In someembodiments, the barrier salt layer contains a mixture of two or moreinorganic sulfate salts. In one embodiment, the barrier salt layercontains a mixture of sodium sulfate and magnesium sulfate.

In some embodiments, the granules further contain an outer coating layercontaining a polymer coated over the barrier salt layer. The outercoating layer optionally further contains a pigment in addition to thepolymer. In one embodiment, the polymer is a polyvinyl alcohol.

In some embodiments, the granules contain an outer coating layercontaining a pigment coated over the barrier salt later.

In another aspect, the invention provides a composition containing apopulation of enzyme-containing granules as described above. In someembodiments, the composition is a detergent composition. In someembodiments, the composition is a textile processing composition. Insome embodiments, the composition is an animal feed composition.

In another aspect, the invention provides a method of makingenzyme-containing granules, including coating an enzyme-containing layeronto cores in a fluidized bed spray coater. At least about 95% of thegranules produced by the method contain a single core consisting of oneor more inorganic salts. In some embodiments, at least about 50%, 60%,70%, 80%, or 90% of the granules produced by the method contain adiameter of about 150 to about 300 microns. In some embodiments, atleast about 50%, 60%, 70%, 80%, or 90% of the granules produced by themethod contain a diameter of about 200 to about 350 microns. In someembodiments, at least about 50%, 60%, 70%, 80%, or 90% of the granulescontain a diameter of about 150 to about 355 microns.

In one embodiment of the method, the cores consist of sodium sulfate. Insome embodiments, at least about 80% or 90% of the cores contain adiameter of about 150 to about 250 microns. In some embodiments, atleast about 80% or 90% of the cores contain a diameter of about 200 toabout 300 microns. In some embodiments, the cores contain a bulk densitygreater than about 1.2 g/ml. In some embodiments, the cores contain abulk density greater than about 1.2 or 1.4 g/ml. In some embodiments,the cores are pre-sieved to a particle dispersity index of about 2.0 orless, 2.5 or less, or 3.0 or less.

In some embodiments, the method further includes coating a layercontaining a barrier salt over the enzyme-containing layer, wherein thegranules are not removed from the fluidized bed spray coater prior toaddition of the barrier salt layer. In one embodiment, the barrier saltlayer contains sodium sulfate. In some embodiments, the barrier saltlayer contains a mixture of two or more salts. In some embodiments, thebarrier salt layer contains a mixture of two or more inorganic sulfatesalts. In one embodiment, the barrier salt layer contains a mixture ofsodium sulfate and magnesium sulfate. In some embodiments, the methodfurther includes coating an outer coating layer containing a polymer,and optionally further containing a pigment, over the barrier saltlayer, wherein the granules are not removed from the fluidized bed spraycoater prior to addition of the outer coating layer. In one embodiment,the polymer is a polyvinyl alcohol. In some embodiments, the methodfurther includes coating an outer coating layer containing a pigmentover the barrier salt later, wherein the granules are not removed fromthe fluidized bed spray coater prior to addition of the outer coatinglayer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts particle size distribution for enzyme granules preparedas described in Examples 1-4.

DETAILED DESCRIPTION

The invention provides methods for the production of small coated,substantially discrete (i.e., substantially non-agglomerated)enzyme-containing granules in a top-spray fluidized bed coating process,and enzyme-containing granules produced by the methods.

Enzyme-containing granules as described herein may be used inapplications such as cleaning (e.g., detergents), textile processing,food (e.g., baking), animal feed, and fuel ethanol production.

Enzyme-containing Granules

The invention provides small enzyme-containing granules. A granule ofthe invention includes a single, discrete core and an enzyme-containinglayer coated over the core. The core consists of one or more inorganicsalts. In one embodiment, the core consists of sodium sulfate. Thediameter of an enzyme granule of the invention is about 150 μm to about300 μm, about 150 μm to about 350 μm, about 150 μm to about 355 μm,about 180 μm to about 300 μm, about 180 μm to about 350 μm, about 210 μmto about 350 μm, about 212 μm to about 355 μm, or about 180 μm to about355 μm. In various embodiments, the diameter of an enzyme granule is anyof about 150, 160, 170, 180, 190, 200, or 210 μm to any of about 250,260, 270, 280, 290, 300, 310, 320, 330, 340, 350, or 355 μm. Thediameters of the salt cores in the granules is about 100 μm to about 250μm, about 150 μm to about 250 μm, or about 250 μm to about 300 μm.Enzyme-containing granules of the invention are produced in a fluid bedspray coater.

The enzyme layer contains one or more enzymes. The enzyme layer may alsocontain one or more of a polymer, a sugar, a starch, and a surfactant.

In some embodiments, an enzyme-containing granule includes a barrierlayer coated over the enzyme layer to insulate or impede transport ofwater and inactivating substances to the enzyme and/or to improvemechanical strength and reduce friability of the granule. A barrierlayer contains a salt (e.g., sodium sulfate), a polysaccharide (e.g.,starch), a sugar (e.g., sucrose), or a combination thereof.

In some embodiments, an enzyme-containing granule includes an outercoating layer. The outer coating layer may be coated over the enzymelayer or may be coated over a barrier layer. An outer coating layer mayserve any of a number of functions in an enzyme-containing granule,depending on the end use of the granule. For example, an outer coatingmay render the enzyme resistant to oxidation by bleach, bring about adesirable rate of dissolution upon introduction of the granule into anaqueous medium, provide a barrier against ambient moisture in order toenhance the storage stability of the enzyme, and/or improve mechanicalstability and reduce tendency of the granule to break down and formdust. An outer coating layer may contain a polymer, for example,polyvinyl alcohol, and/or a pigment.

In some embodiments, the enzyme-containing granules contain about 50% toabout 70% inorganic salt core (for example, sodium sulfate), about 1% toabout 25% enzyme solids layer (for example, enzyme and one or more ofsucrose, starch, surfactant, and polymer, about 10% to about 20% barrierlayer (for example, a salt such as sodium sulfate or a mixture of two ormore salts such as a mixture of sodium sulfate and magnesium sulfate)and/or about 5 to about 10% outer coating layer (for example, a layercontaining polymer and/or pigment, such as polyvinyl alcohol, titaniumdioxide, and surfactant, or polyvinyl alcohol and talc) by weight. Insome embodiments, the granules contain enzyme in an amount that is about0.5 to about 25% of the weight of the granule, for example, about 0.5,1, 2, 5, 10, 15, 20, or 25% of the weight of the granule.

The invention also provides a population of enzyme-containing granules,with at least about 95%, 98%, or 99% of the granules in the populationcontaining a single, discrete core consisting of one or more inorganicsalts and an enzyme layer coated over the core. In a population ofgranules as described herein, at least about 50%, 60%, 70%, 80%, 85%,90%, or 95% of the granules have a diameter of about 150 μm to about 300μm, about 150 μm to about 350 μm, about 150 μm to about 355 μm, about180 μm to about 300 μm, about 180 μm to about 350 μm, about 210 μm toabout 350 μm, about 212 μm to about 355 μm, or about 180 μm to about 355μm. In some embodiments, at least about 50%, 60%, 70%, 80%, 85%, 90%, or95% of the granules have a diameter of any of about 150, 160, 170, 180,190, 200, or 210 μm to any of about 250, 260, 270, 280, 290, 300, 310,320, 330, 340, 350, or 355 μm.

In some embodiments, a population of enzyme-containing granules asdescribed herein contains a particle size dispersity index of about 2.0or less, about 2.5 or less, or about 3.0 or less. “Particle sizedispersity index” (“PSDI”) as used herein refers to the ratio ofparticle diameters of the 90^(th) weight-average percentile (D90) to theweight-average 10^(th) percentile (D10) in a sample. 10% by weight ofthe particles in the sample are greater than the D90 diameter and 10% byweight of the particles in the sample are less than the D10 diameter.

In some embodiments, the dust level generated by a population ofgranules as described herein, as measured by the Heubach test, is lessthan about 50, 40, 30, 20, 10, or 5 mg/pad.

Salt Core

The core of an enzyme-containing granule as described herein consists ofone or more inorganic salts. In some embodiments, the core consists ofsodium sulfate, sodium citrate, sodium chloride, calcium sulfate, or acombination thereof. In one embodiment, the core consists of sodiumsulfate.

The salt core of an enzyme-containing granule as described herein has adiameter of about 100 μm to about 250 μm, about 150 μm to about 250 μm,or about 250 μm to about 300 μm.

In some embodiments, prior to preparation of a population ofenzyme-containing granules, salt cores are pre-sieved to a particle sizedispersity index of about 2.0 or less, about 2.5 or less, or about 3.0or less. Pre-sieving may be performed using methods known in the art,for example, using a vibratory sieve shaker or pneumatic classifier. Forexample, cores may be pre-sieved, by conventional sieving through a 250μm sieve, collecting the fraction from above the 150 μm sieve, anddiscarding or recycling fines that pass through the 150 μm sieve.Pre-sieving may also be performed in a fluid bed coater by blowing thefines out with the air flow. The air flow can be adjusted so that thedesired core size will be retained.

Typically, the salt core has a bulk density greater than about 1.0 g/ml.In some embodiments, the bulk density is greater than 1.2 g/ml. In someembodiments, the bulk density is greater than about 1.4 g/ml. In someembodiments, the bulk density is any of about 1.0, 1.2, or 1.4 g/ml toany of about 1.6, 1.7 or 1.8 g/ml. Bulk density may be measured as“poured bulk density” or “non-tapped bulk density” by filling agraduated cylinder with a known volume of particles, measuring the massof the particles in the cylinder, and calculating bulk density bydividing the mass by the volume.

Enzyme Layer

A single enzyme or a combination of two or more enzymes may be includedin the enzyme layer of granules as described herein. In someembodiments, the enzyme layer includes an enzyme that is capable ofhydrolyzing a substrate, e.g., a stain. Such an enzyme is typically ahydrolase, for example, a protease (bacterial (e.g., a subtilisin) orfungal; acid, neutral, or alkaline), an amylase (alpha or beta), alipase, or a cellulase. In some embodiments, the enzyme is a subtilisin,for example, as described in U.S. Pat. No. 4,760,025, EP Patent No. 130756, or PCT Application No. WO 91/06637. In some embodiments, the enzymeis a cellulase, for example, Multifect L250™ or Puradax™, commerciallyavailable from Danisco US, Inc., Genencor Division. In some embodiments,the enzyme layer includes an oxidase, an oxygenase, a transferase, adehydratase, a reductase, a hemicellulase, a peroxidase, aphospholipase, an esterase, a cutinase, a pectinase, a keratinase, alipoxygenase, a ligninase, a pullulanase, a tannase, a pentosanase, amalanase, a β-glucanase, an arabinosidase, a hyaluronidase, achondroitinase, a laccase, a catalase, an isomerase, a pectate lyase, ora mannanase, or a combination thereof. In some embodiments, the enzymelayer includes a phytase. In some embodiments, the enzyme layer includesa perhydrolase enzyme, such as, for example, an enzyme as described inPCT Application No. WO 05/056782. In some embodiments, the enzyme layerincludes one or more enzymes sold under the trade names Purafect™,Purastar™, Properase™, Puradax™, Clarase™, Multifect™, Maxacal™,Maxapem™, and Maxamyl™ by Danisco US, Inc, Genencor Division. (see U.S.Pat. No. 4,760,025 and PCT Application No. WO 91/06637); Alcalase™,Savinase™, Primase™, Durazyme™, Duramyl™, Ovozyme™, Polarzyme™, andTermamyl™ sold by Novo Industries A/S (Denmark).

The enzyme layer may also optionally include one or more othercomponents in addition to the enzyme(s). Such non-enzyme componentsinclude, but are not limited to, polymers (e.g., polyvinyl alcohol,polyethylene glycol), sugars (e.g., sucrose, saccharose, glucose,fructose, galactose, maltodextrin), starches (e.g., corn starch, wheatstarch, tapioca starch, potato starch, chemically or physically modifiedstarch), dextrins, antifoam agents (e.g., polyether polyols such asFoamblast 882 (Emerald Foam Control), Erol DF 204K (Ouvrie PMC), DG436(ODG Industries, Inc.), KFO 880 (KABO Chemicals, Inc.)), sugar alcohols(e.g., sorbitol, maltitol, lactitol, xylitol), surfactants (e.g.,alcohol ethoxylates such as Neodol 23-6.5 (Shell Chemical LP, Houston,Tex.) and Lutensol TO65 (BASF)), and anti-redeposition agents (e.g.,polyethylene glycol polyesters such as Repel-o-Tex SRP6 (Rhodia, Inc.),Texcare SRN-100 or SRN-170 (Clariant GmbH, Sorez-100(ISP Corp.)).

An “antifoam agent” is a compound that is used to prevent or break foam.These can also be referred to as defoamers, or defoaming agents. Thesecompounds are surface active substances which decrease the surfaceelasticity of liquids and prevent metastable foam formation. The foambreaks as a result of the tendency to attain the equilibrium between thesurface elasticity of the liquid and the surface active substances.(Vardar-Sukan (1991) Recent Adv. Biotechnol. 113-146) Antifoams usefulin the granules described herein are generally suitable for use in abioprocess. Suitable antifoam agents include, but are not limited to,fats, oils, waxes, aliphatic acids or esters, alcohols, sulfates,sulfonates, fatty acids, soaps, nitrogenous compounds, phosphates,polyglycols, sulfides, thio compounds, siloxanes and halogenated andinorganic compounds. (Ghildyal (1988) Adv. Appl. Microbiol. (1988)33:173-222). In some embodiments, oils, fatty acids, esters, polyglycolsand siloxanes are useful. In some embodiments, the antifoam agent isethylene oxide propylene oxide copolymer. In one embodiment, theethylene oxide propylene oxide copolymer has an approximate molecularweight of 2200 (e.g., available as Mazu™ from Mazer Chemicals, Inc.).

Barrier Layer

In some embodiments, a barrier layer is coated over the enzyme layer inan enzyme-containing granule as described herein. In some embodiments,the barrier layer contains one or more salts, for example, sodiumsulfate, sodium citrate, magnesium sulfate, potassium sulfate, and/orammonium sulfate. In some embodiments, the barrier layer comprises,consists of, or consists essentially of sodium sulfate. In someembodiments, the barrier layer comprises, consists of, or consistsessentially of a mixture of sodium sulfate and magnesium sulfate. Insome embodiments, the barrier layer contains a sugar (e.g., sucrose), apolysaccharide (e.g., starch), or a combination thereof.

In some embodiments, the barrier layer contains a mono-, di-, ortrivalent water soluble inorganic sulfate salt, e.g., sodium, potassium,ammonium, magnesium, aluminum, ferrous, and/or ferric sulfate salt(s) ora mixture of two or more soluble inorganic sulfate salts.

In some embodiments, the barrier layer is a mixture of two salts withone salt present at any of at least about 50%, 60%, 70%, 80%, or 90% byweight relative to the total weight of the barrier layer. In someembodiments, the two salts are present in a ratio of about 50:50, 55:45,60:40, 65:35, or 70:30 by weight of the barrier layer. In oneembodiment, the mixture of two salts is a mixture of sodium sulfate andmagnesium sulfate. In some embodiments, the barrier layer consists ofsodium sulfate and magnesium sulfate in a ratio of about 30:70 to about70:30 by weight of the barrier layer, for example, 30:70, 35:65, 40:60,45:55, 50:50, 55:45, 60:40, 65:35, or 70:30.

In some embodiments, the barrier layer is hydrated. The term “hydrated”means that the barrier material contains water in a free or bound form,or a combination of the two. The water of hydration can be added eitherduring or after the coating process. The degree of hydration will be afunction of the material itself and the temperature, humidity and dryingconditions under which it is applied.

“Moderate or high” water activity means having a water activity of atleast about 0.25, 0.30, or 0.35. The water activity referred to hereinis that of the granule itself once it has the barrier material—but nofurther coatings—coated onto it. Further coatings may mask accuratemeasurement of the water activity of the barrier material as a distinctlayer.

Without wishing to be bound by theory, it is expected that materialswith a water activity greater than 0.25 will have a reduced drivingforce for picking up water under storage conditions in which therelative humidity is greater than 25%. Most climates have relativehumidities above 25%. Many detergents have water activities in the rangeof about 0.3 to 0.4. If the water activity of the granule is actuallyhigher than that of the surrounding detergent or storage climate, thedriving force for pick up of water by the granule should be eliminated,and in fact water may be given up by the granule to its surroundings.Even if the water activity of the granule is lower than that of thedetergent or the corresponding relative humidity, the water present inthe barrier layer would act as a shield limiting the amount of waterbeing picked up by the granule and affecting the protein core.

In the case of salt hydrates, the hydrated material is a crystallinesalt hydrate with bound waters of crystallization. The hydrate should bechosen and applied in a manner such that the resulting coated granulewill have a water activity in excess of 0.25, or as high as possiblewhile still retaining a granule which is dry to the touch. By applying asalt hydrate, or any other suitable hydrated barrier material, in such amanner, one eliminates any driving force for further uptake of water bythe granule. As an important consequence, the driving force fortransport of substances which may be detrimental to enzyme activity,such as perborate or peroxide anion, is removed. Without water as avehicle, these substances are less likely to penetrate the enzyme core.Empirical data demonstrates that enzyme activity in the granule issubstantially enhanced by coating the enzyme core with stable salthydrates.

Examples of suitable salts for production of a hydrated barrier layerinclude magnesium sulfate heptahydrate, zinc sulfate heptahydrate,copper sulfate pentahydrate, sodium phosphate dibasic heptahydrate,magnesium nitrate hexahydrate, sodium borate decahydrate, sodium citratedihydrate and magnesium acetate tetrahydrate.

Outer Coating Layer

In some embodiments, an enzyme containing granule comprises an outercoating layer. In one embodiment, the outer coating layer is coated overthe enzyme layer. In another embodiment, the outer coating layer iscoated over a barrier layer, which is coated over the enzyme layer.

In some embodiments, the outer coating layer includes one or morepolymers. Suitable polymers include, but are not limited to, polyvinylalcohol (PVA), polyvinyl pyrrolidone (PVP), polyvinyl acetate,PVA-methylmethacrylate copolymer, PVP-PVA copolymer, cellulosederivatives such as methylcellulose, hydroxypropylmethyl cellulose,hydroxycellulose, ethylcellulose, caboxymethyl cellulose, hydroxypropylcellulose, polyethylene glycol, polyethylene oxide, chitosan, gumarabic, xanthan, carrageenan, latex polymers, and enteric polymer.

In some embodiments, the outer coating layer includes PVA. Suitable PVAsfor incorporation in the outer coating layer include partiallyhydrolyzed, fully hydrolyzed, and intermediately hydrolyzed PVAs havinglow to high degrees of viscosity. (See, e.g., U.S. Pat. No. 5,324,649.)In one embodiment, the outer coating layer includes partially hydrolyzedPVA having low viscosity.

In some embodiments, the outer coating layer includes one or morepigments. Nonlimiting examples of suitable pigments include finelydivided whiteners, such as titanium dioxide or calcium carbonate,calcium sulfate, talc, or colored pigments or dyes. Typically, suchpigments are low residue pigments upon dissolution. In addition topolymers and/or pigments, the outer coating layer may also include oneor more of plasticizers, extenders, lubricants, surfactants, andanti-redeposition agents.

Suitable plasticizers include, but are not limited to, polyols (e.g.,sugars, sugar alcohols, polyethylene glycols (PEGs), glycol, propyleneglycol), urea, triethyl citrate, dibutyl or dimethyl phthalate, orwater.

Suitable extenders include, but are not limited to, sugars (e.g.,sucrose or starch hydrolysates, such as maltodextrin or corn syrupsolids), clays (e.g., kaolin or bentonite), and talc. An “extender” is asubstance (generally lower cost) added to another substance (generallyhigher cost and higher performance) to modify or dilute it.

Suitable lubricants include, but are not limited to, nonionicsurfactants (e.g., Neodol, Lutensol TO 65), tallow alcohols, fattyacids, fatty acid salts (e.g., magnesium stearate), and fatty acidesters.

Suitable surfactants include, but are not limited to, alcoholethoxylates such as Neodol 23-6.5 and Lutensol TO65.

Suitable anti-redeposition agents include, but are not limited to,polyethylene glycol polyesters such as Repel-o-Tex SRP6, Texcare SRN-100or SRN-170, and Sorex-100.

Methods of Making Enzyme Granules

The invention provides methods for producing enzyme-containing granulesas described above, with high coating efficiency and minimalagglomeration. The methods comprise coating an enzyme-containing layeronto inorganic salt cores in a fluidized bed spray coater. Optionally,the method also comprises coating a barrier layer onto theenzyme-containing layer, coating an outer coating layer onto theenzyme-containing layer, or coating a barrier layer onto theenzyme-containing layer and an outer coating layer onto the barrierlayer, in the fluidized bed spray coater. At least about 95%, 98%, or99% of the enzyme-containing granules produced in accordance with themethods described herein contain a single, discrete core (i.e., are notagglomerated and contain a ratio of granule to core of 1:1). In oneembodiment, the inorganic salt cores consist of sodium sulfate.

In methods of the invention, the particle size distribution, shape, anddensity of the salt cores are controlled, permitting production ofsmall, substantially discrete, coated granules. In some embodiments,this is achieved by pre-selecting or pre-sieving the initial charge ofcores to a PSDI of about 2.0 or less, about 2.5 or less, or about 3.0 orless, prior to introduction into the fluidized bed spray coater. Thesalt cores comprise a bulk density greater than about 1.0, 1.2, or 1.4g/ml, which results in more controlled fluidization and coatingefficiency in the top-spray coater than salt cores with a lower bulkdensity. These factors of controlled size distribution and bulk densityof the salt cores result in a controlled fluidization pattern withsufficient expansion of the bed (to avoid agglomeration), butminimization of physical elutriation (loss of particles into filters,scrubbers, or the exit air stream). In some embodiments, the air flow,spray rate, bed temperature, and/or atomization air pressure of thefluid bed coater are adjusted to substantially prevent agglomeration.

The enzyme-containing granules may be prepared in a continuous ordiscontinuous process. In a continuous process, the enzyme layer andbarrier and/or outer coating layers are coated over the salt corewithout removal of the granules from the spray coater. In adiscontinuous process, the granules are removed from the spray coaterand re-introduced into a spray coater prior to addition of a barrierand/or outer coating layer.

A continuous process as described herein has the advantage of permittingpreparation of discrete small enzyme granules within a single efficientoperation of a fluid bed coater, requiring no separate preparation ofenzyme particles before the coating step, or removal of unfinishedproduct from the coater for addition of further coating layers in asubsequent operation. By eliminating the need to transfer uncoatedenzyme cores between operations, this single contained processeliminates downtime and transfer losses, and minimizes the exposure ofoperators in the manufacturing plant to unsafe levels of airborn enzymedusts and aerosols.

At least about 50%, 60%, 70%, 80%, 85%, 90%, or 95% of the granulesproduced in the methods described herein have a diameter of about ofabout 150 μm to about 300 μm, about 150 μm to about 350 μm, about 150 toabout 355 μm, about 180 μm to about 300 μm, about 180 μm to about 350μm, about 210 μm to about 350 μm, about 212 μm to about 355 μm, or about180 μm to about 355 μm. In some embodiments, at least about 50%, 60%,70%, 80%, 85%, 90%, or 95% of the granules have a diameter of any ofabout 150, 160, 170, 180, 190, 200, or 210 μm to any of about 250, 260,270, 280, 290, 300, 310, 320, 330, 340, 350, or 355 μm.

In some embodiments, a population of enzyme-containing granules producedby a method as described herein contains a particle size dispersityindex of about 2.0 or less, about 2.5 or less, or about 3.0 or less.

Compositions

The invention provides compositions containing enzyme-containinggranules as described above. In addition to the enzyme-containinggranules, the compositions contain components suitable for use of thegranules in particular applications, such as cleaning (e.g.,detergents), textiles, or animal feed.

Cleaning Compositions

In some embodiments, enzyme-containing granules as described herein areincorporated into a cleaning composition, such as a detergent, e.g., forlaundry or dishwashing use, to provide cleaning performance and/orcleaning benefits. Enzymes suitable for inclusion in a cleaningcomposition include, but are not limited to, hemicellulases,peroxidases, proteases, cellulases, xylanases, lipases, phospholipases,esterases, cutinases, pectinases, keratinases, reductases, oxidases,phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases,pentosanases, malanases, β-glucanases, arabinosidases, hyaluronidase,chondroitinase, laccases, perhydrolases, and amylases, or mixturesthereof. A typical combination is a cocktail of conventional applicableenzymes like protease, lipase, cutinase and/or cellulase in conjunctionwith amylase.

Adjunct materials may also be included in the cleaning composition, forexample, to assist or enhance cleaning performance, for treatment of thesubstrate to be cleaned, or to modify the aesthetics of the cleaningcomposition as is the case with perfumes, colorants, dyes or the like.It is understood that such adjuncts are in addition to theenzyme-containing granules as described herein. The precise nature ofthese additional components, and levels of incorporation thereof, willdepend on the physical form of the composition and the nature of thecleaning operation for which it is to be used. Suitable adjunctmaterials include, but are not limited to, surfactants, builders,chelating agents, dye transfer inhibiting agents, deposition aids,dispersants, enzyme stabilizers, catalytic materials, bleach activators,bleach boosters, preformed peracids, polymeric dispersing agents, claysoil removal/anti-redeposition agents, brighteners, suds suppressors,dyes, perfumes, structure elasticizing agents, fabric softeners,carriers, hydrotropes, processing aids and/or pigments. In addition tothe disclosure below, suitable examples of such other adjuncts andlevels of use are described in U.S. Pat. Nos. 5,576,282, 6,306,812, and6,326,348.

Surfactants—A cleaning composition as described herein may comprise asurfactant or surfactant system wherein the surfactant can be selectedfrom nonionic surfactants, anionic surfactants, cationic surfactants,ampholytic surfactants, zwitterionic surfactants, semi-polar nonionicsurfactants, and mixtures thereof. A surfactant is typically present ata level of about 0.1% to about 60%, about 1% to about 50% or about 5% toabout 40% by weight of the subject cleaning composition.

Builders—A cleaning composition as described herein may comprise one ormore detergent builder or builder system. When a builder is used, thesubject cleaning composition will typically comprise at least about 1%,about 3% to about 60%, or about 5% to about 40% builder by weight of thesubject cleaning composition.

Builders include, but are not limited to, the alkali metal, ammonium andalkanolammonium salts of polyphosphates, alkali metal silicates,alkaline earth and alkali metal carbonates, aluminosilicate builders,polycarboxylate compounds. ether hydroxypolycarboxylates, copolymers ofmaleic anhydride with ethylene or vinyl methyl ether, 1,3,5-trihydroxybenzene-2,4,6-trisulphonic acid, and carboxymethyloxysuccinic acid, thevarious alkali metal, ammonium and substituted ammonium salts ofpolyacetic acids such as ethylenediamine tetraacetic acid andnitrilotriacetic acid, as well as polycarboxylates such as melliticacid, succinic acid, citric acid, oxydisuccinic acid, polymaleic acid,benzene 1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, andsoluble salts thereof.

Chelating Agents—A cleaning composition as described herein may containone or more chelating agent. Suitable chelating agents include, but arenot limited to, copper, iron and/or manganese chelating agents andmixtures thereof. When a chelating agent is used, the cleaningcomposition may comprise about 0.1% to about 15%, or about 3.0% to about10% chelating agent by weight of the subject cleaning composition.

Deposition Aids—A cleaning composition as described herein may containone or more deposition aid. Suitable deposition aids include, but arenot limited to, polyethylene glycol, polypropylene glycol,polycarboxylate, soil release polymers such as polytelephthalic acid,and clays such as Kaolinite, montmorillonite, atapulgite, illite,bentonite, halloysite, and mixtures thereof.

Dye Transfer Inhibiting Agents—A cleaning composition as describedherein may include one or more dye transfer inhibiting agent. Suitablepolymeric dye transfer inhibiting agents include, but are not limitedto, polyvinylpyrrolidone polymers, polyamine N-oxide polymers,copolymers of N-vinylpyrrolidone and N-vinylimidazole,polyvinyloxazolidones, and polyvinylimidazoles, and mixtures thereof.When present in a subject cleaning composition, dye transfer inhibitingagent may be present at levels of about 0.0001% to about 10%, about0.01% to about 5%, or about 0.1% to about 3% by weight of the cleaningcomposition.

Dispersants—A cleaning composition as described herein may contain oneor more dispersant. Suitable water-soluble organic dispersants include,but are not limited to, the homo- or co-polymeric acids or their salts,in which the polycarboxylic acid comprises at least two carboxylradicals separated from each other by not more than two carbon atoms.

Enzyme Stabilizers—Enzymes for use in detergents can be stabilized byvarious techniques. Enzymes employed herein can be stabilized, forexample, by the presence of water-soluble sources of calcium and/ormagnesium ions in the finished compositions that provide such ions tothe enzymes.

Catalytic Metal Complexes—A cleaning composition as described herein mayinclude one or more catalytic metal complex. One type ofmetal-containing bleach catalyst is a catalyst system comprising atransition metal cation of defined bleach catalytic activity, such ascopper, iron, titanium, ruthenium, tungsten, molybdenum, or manganesecations, an auxiliary metal cation having little or no bleach catalyticactivity, such as zinc or aluminum cations, and a sequestrate havingdefined stability constants for the catalytic and auxiliary metalcations, particularly ethylenediaminetetraacetic acid,ethylenediaminetetra (methylenephosphonic acid) and water-soluble saltsthereof. Such catalysts are disclosed in U.S. Pat. No. 4,430,243.Manganese-containing catalysts useful herein are known, and aredescribed, for example, in U.S. Pat. No. 5,576,282. Cobalt bleachcatalysts useful herein are known, and are described, for example, inU.S. Pat. Nos. 5,597,936 and 5,595,967. Such cobalt catalysts arereadily prepared by known procedures, such as taught for example in U.S.Pat. Nos. 5,597,936 and U.S. Pat. No. 5,595,967.

Compositions herein may also include a transition metal complex of amacropolycyclic rigid ligand—abreviated as “MRL”. As a practical matter,and not by way of limitation, the compositions and cleaning processesherein can be adjusted to provide on the order of at least one part perhundred million of the active MRL species in the aqueous washing medium,and will often provide about 0.005 ppm to about 25 ppm, about 0.05 ppmto about 10 ppm, or about 0.1 ppm to about 5 ppm, of the MRL in the washliquor. Suitable transition-metals in a transition-metal bleach catalystinclude manganese, iron and chromium. In one embodiment, an MRL is anultra-rigid ligand that is cross-bridged, such as5,12-diethyl-1,5,8,12-tetraazabicyclo[6.6.2] hexadecane. Suitabletransition metal MRLs are readily prepared by known procedures, such astaught for example in PCT Application No. WO 00/332601 and U.S. Pat. No.6,225,464.

The cleaning compositions disclosed herein of can be used to clean asitus on a surface or fabric. Typically at least a portion of the situsis contacted with a cleaning composition as described above, in neatform or diluted in a wash liquor, and then the situs is optionallywashed and/or rinsed. Washing includes, but is not limited to,scrubbing, and mechanical agitation. A fabric may comprise most anyfabric capable of being laundered in normal consumer use conditions. Thedisclosed cleaning compositions are typically employed at concentrationsof from about 500 ppm to about 15,000 ppm in solution. When the washsolvent is water, the water temperature typically ranges from about 5°C. to about 90° C. and, when the situs comprises a fabric, the water tofabric mass ratio is typically from about 1:1 to about 30:1.

Textile Processing Compositions

In some embodiments, enzyme-containing granules as described herein areincorporated into a textile processing composition. Enzymes suitable forinclusion in a textile processing composition include, but are notlimited to, cellulases, perhydrolases, polyesterases, amylases, phenoloxidizing enzymes (e.g., laccases), and catalases. In some embodiments,a textile processing composition may also include an anti-redepositionagent (e.g., Repel-O-Tex, Sorez 100 (ISP Corp.).

Animal Feed Compositions

In some embodiments, enzyme-containing granules as described herein areincorporatec into an animal feed composition. Enzymes suitable forinclusion in a feed composition include cellulolytic and/orhemicellulolytic enzymes. Nonlimiting examples of enzymes suitable forincorporation into a feed composition include phytases, xylanases,phosphatases, proteases, amylases, esterases, redox enzymes, lipases,transferases, cellulases, phospholipases, ligninases, and β-glucanases.

The following examples are intended to illustrate, but not limit, theinvention.

EXAMPLES Example 1

2296 grams of sodium sulfate crystals, with a particle diameter sizerange of 150 μm to 250 μm, was loaded into a Vector FL-1 fluid bedcoater and fluidized. To this, 5557 grams of a solution containing23,608 U/ml of active neutral cellulase, 3.6% Sorez-100 from ISP Corp.(an anti-redeposition agent), and 0.36% polyvinyl alcohol (5/88 fromErkol) was spray-coated onto the sodium sulfate crystals.

The spray coating parameters were as follows:

Solution Spray Rate 6.5 gpm (grams per minute), increasing to 15.4 gpmover 2.5 hours. Kept at 15.4 gpm for remainder of experiment. InletTemperature 85° C., increased to 90° C. after 1 hour Outlet temperatureBetween 42° C. and 46° C. Fluidization Air Flow 50 cfm (cubic feet perminute) Atomization Air Pressure 40 pounds per square inch (psi),increasing to 50 psi over 2.5 hours.

3017 grams of product was harvested, of which 2899 grams passed througha 40 mesh sieve (425 μm). The particle size distribution is shown inTable 1 and in FIG. 1.

TABLE 1 Particle Size Analysis for Enzyme Granules Produced in Example 1Amount of Particle size (μm) particles (%) Over 425 3.8 354-425 1.1297-354 2.6 210-297 59.0 149-210 34.5 Under 149 0.4

Example 2

1395 grams of the enzyme granules produced in Example 1 were loaded intoa Vector FL-1 fluid bed coater and fluidized. 861 grams of an aqueoussolution containing 172 grams of sodium sulfate were then spray coatedonto the enzyme granules.

The spray coating parameters were as follows:

Solution Spray Rate 14.9 gpm Inlet Temperature 90° C. Outlet temperatureBetween 42° C. and 46° C. Fluidization Air Flow 53 cfm Atomization AirPressure 40 psi

1483 grams of final product was harvested. The particle sizedistribution is shown in Table 2 and in FIG. 1.

TABLE 2 Particle Size Analysis for Enzyme Granules Produced in Example 2Amount of Particle size (μm) particles (%) Over 425 3.8 354-425 0.0297-354 0.3 210-297 67.1 149-210 28.7 Under 149 0.1

Example 3

1395 grams of the enzyme granules produced in Example 2 were loaded intoa Vector FL-1 fluid bed coater and fluidized. 861 grams of an aqueoussolution containing 52 grams of PVA (Erkol 5/88), 112 grams of talc(Nytal 400), and 8.6 grams of Neodol 23/6.5 were then spray coated ontothe enzyme granules.

The spray coating parameters were as follows:

Solution Spray Rate 10.8 gpm Inlet Temperature 95° C. Outlet temperatureBetween 49° C. and 50° C. Fluidization Air Flow 50 cfm Atomization AirPressure 46 psi

1477 grams of final product was harvested. The particle sizedistribution is shown in Table 3 and in FIG. 1.

TABLE 3 Particle Size Analysis for Enzyme Granules Produced in Example 3Amount of Particle size (μm) particles (%) Over 425 9.2 354-425 8.6297-354 7.4 210-297 64.5 149-210 10.4 Under 149 0.0

Example 4

2820 grams of unsifted sodium sulfate crystals (from Urumqi Huagao TradeCo., Ltd., Urumqi City, China (“Hanhua Grade C”)) were loaded into aVector FL-1 fluid bed coater and air sifted, i.e., fluidized for 30minutes. Unsifted Hanhua Grade C sodium sulfate crystals had thefollowing particle size distribution:

Screen (μm) Max % Min % 355 0 0 280 0 0 250 25 5 200 43 22 150 89 80After the fluidization, 2660 grams of sodium sulfate crystals remained.

2287 grams of the air sifted sodium sulfate crystals were loaded into aVector GL-1 fluid bed coater and fluidized. 5670 grams of a solutioncontaining 23,608 U/ml of active neutral cellulase, 3.6% Sorez-100 ISPCorp.), and 0.36% polyvinyl alcohol (5/88 from Erkol) was spray-coatedonto the sodium sulfate crystals.

The spray coating parameters were as follows:

Air-sifting of Sulfate Crystals

Inlet Temperature 85° C. Fluidization Air Flow 52 cfm Atomization AirPressure 20 psi

Enzyme Solution Spray Coating

Solution Spray Rate 7.2 gpm, increasing to 15.5 gpm over 2.5 hours. Keptat 15.5 gpm for remainder of experiment. Inlet Temperature 85° C. Outlettemperature Between 39° C. and 48° C. Fluidization Air Flow 50 cfmAtomization Air Pressure 40 psi

3057 grams of product was harvested, of which 2952 grams passed througha 40 mesh sieve.

The particle size distribution is shown in Table 4 and in FIG. 1.

TABLE 4 Particle Size Analysis for Enzyme Granules Produced in Example 4Amount of Particle size (μm) particles (%) Over 425 3.4 354-425 1.2297-354 2.5 210-297 76.4 149-210 16.4 Under 149 0.1

Example 5

149 kg of sodium sulfate crystals (Hanhua Grade C, particle sizedistribution described in Example 4), with a size range of 150 μm to 250μm, was loaded into a pilot fluid bed coater with a bowl volume ofapproximately 93 liters and three spray nozzles and fluidized. 66 kg ofa mixture of EG3 cellulase (216 U/g), sucrose (2.6 kg), and wheat starch(2.6 kg) was spray-coated onto the sodium sulfate crystals. 120 kg ofsodium sulfate solution (25% in water) was then sprayed onto the enzymecontaining layer.

The spray coating parameters were as follows:

Warm-up:

Inlet Air Temperature 70° C. Fluidization Air Flow 1175 Nm³/h (nominalor norm m³ of air per hour) Atomization Air Pressure 5.5 bar

Enzyme Solution Spray Coating:

Solution Spray Rate 18.0 l/h for 20 minutes, then increasing to 33.0 l/hover 110 minutes. Kept at 33.0 l/h for remainder of the experiment. BedTemperature 50° C. Fluidization Air Flow 1300 Nm³/h, then increasing to1325 Nm³/h over 75 minutes Atomization Air Pressure 5.5 bar

Sulfate Solution Spray Coating:

Solution Spray Rate 36 l/h, then increasing to 51 l/h over 35 minutes.Kept at 51 l/h for remainder of the experiment. Bed Temperature 52° C.Fluidization Air Flow 1325 Nm³/h, then increasing to 1375 Nm³/h over 60minutes Atomization Air Pressure 4.0 bar

145 kg of granules were harvested, of which 94% were smaller than 300 μmand 59% were smaller than 250 μm. The particle size distribution isshown in Table 5.

TABLE 5 Particle Size Analysis for Enzyme Granules Produced in Example 5Amount of Particle size (μm) particles (%) Over 355 1.1 300-355 4.9250-300 34 212-250 51 180-212 9.2 Under 150 0

Example 6

3156 kg of sodium sulfate crystals (Hanhua Grade C, particle sizedistribution described in Example 4), with a size range of 150 μm to 250μm, was loaded into a top spray fluid bed coater with a 5.6 m³ bowl andfluidized. 8681 kg of a mixture of neutral cellulase (19062 U/g),polyvinyl alcohol (Celvol E 5/88 from Celanese; 204 kg of 10% solutionin water) and Repel-o-Tex (block copolymer of polyethylene glycol andpolyester, from Rhodia; 670 kg of 21% suspension in water) wasspray-coated onto the sodium sulfate crystals. 1462 kg of sodium sulfatesolution (25% in water) was sprayed onto the enzyme containing layer.

The spray coating parameters were as follows:

Warm-up:

Inlet Air Temperature 80° C. Fluidization Air Flow 23000 Nm³/hAtomization Air Pressure 5.0 bar

Enzyme Solution Spray Coating:

Solution Spray Rate 420 l/h for 20 minutes, then increasing to 910 l/hover 2 hours. Kept at 910 l/h for remainder of the experiment. BedTemperature 45-48° C. Fluidization Air Flow 23000 Nm³/h Atomization AirPressure 5.0 bar

Sulfate Solution Spray Coating:

Solution Spray Rate 896 l/h for 5 minutes, then increasing to 1120 l/hover 25 minutes. Kept at 1120 l/h for remainder of the experiment. BedTemperature 45° C. Fluidization Air Flow 23000 Nm³/h Atomization AirPressure 3.5 bar

2950 kg of granules were harvested through a 355 μm sieve. The finalproduct small r than 355 μm in diameter had 88% of particles smallerthan 300 μm, 1.0% smaller than 212 μm, 0.02% smaller than 180 μm, andnone below 150 μm. The mean particle size was 276 μm.

Example 7 Small Neutral Cellulase Based Granules Made at LaboratoryScale 1. Preparation of Enzyme Granules (“Enzyme Coated Cores”)

5,008 grams of Indiage XL neutral cellulase concentrate was mixed with953 grams of Repel-O-Tex SRP6, which had been previously dissolved inwater at 60° C. at a concentration of 19.7%, and 139 grams of PVA(Erkomat), which had been previously dissolved in water at 80° C. at aconcentration of 13.5%. This enzyme/polymer mixture was sprayed onto2,286 grams of Hanhua Grade C sodium sulfate seeds with a size range of150 μm to 250 μm in a Vector FL-1 fluid bed coater using the followingcoating parameters:

Seed Charge 2286 grams Enzyme Feed Rate 9-17 grams/minute AtomizationPressure 40-46 psi Inlet Temperature 80-95° C. Outlet Temperature 40-43°C. Airflow 50-53 cfm

After coating the sodium sulfate seeds with enzyme, enzyme coated coreswere removed from the coater and weighed to determine an overall enzymemass yield. They were also sieved through a 425 micron sieve todetermine mass yield of granules <425 microns. The enzyme mass yield andyield of granules below 425 micron were as follows:

Enzyme Mass Yield: 92.15% <425 microns 94.46% >425 microns (overs) 5.54%The particle size distribution is shown in Table 6.

TABLE 6 Particle Size Analysis for Enzyme Granules Produced in Example7.1 Amount of Particle size (μm) particles (%) Over 355 0.0 300-355 16.3250-300 72.4 212-250 11.0 150-212 0.3 Under 150 0.0

2. Preparation of Sodium Sulfate Coaled Enzyme Granules

Approximately 1,395 grams of the enzyme coated cores made above werereloaded into the coater and were subsequently coated with 861 grams ofsodium sulfate which had been previously dissolved in water at 40° C. ata concentration of 20%. The coating parameters for spraying the saltcores were as follows:

Enzyme Coated Core Charge 1395 grams Feed Rate: 15-16 grams/minuteAtomization Pressure 40 psi Inlet Temperature 90° C. Outlet Temperature40-42° C. Airflow: 52-54 cfm

The overall sodium sulfate layer mass yield and the mass yield ofparticles below and above 425 microns were as follows:

Salt Layer Mass Yield: 88.84% <425 microns 99.74% >425 microns (overs) 0.26%The particle size distribution is shown in Table 7.

TABLE 7 Particle Size Analysis for Enzyme Granules Produced in Example7.2 Amount of Particle size (μm) particles (%) Over 355 1.3 300-355 2.4250-300 12.2 212-250 44.5 180-212 29.7 Under 180 10.0

3. Preparation of PVA/talc Coated Enzyme Granules

Approximately 1,395 grams of the enzyme coated cores made above werereloaded into the coater and were subsequently coated with 517 grams ofa 10% solution of PVA (Erkomat), talc, and Neodol 23-6.5-T (ShellChemical LP, Houston, Tex.) in water which had been previously preparedheated to 80° C. The solution included PVA, talc and neodol 23-6.5-T ina 30:65:5 solids ratio. The coating parameters were as follows:

Enzyme Coated Core Charge 1395 grams Feed Rate 9-11 grams/minuteAtomization Pressure 46 psi Inlet Temperature 94° C. Outlet Temperature52-57° C. Airflow 50 cfm

The overall PVA layer mass yield and the mass yield of particles belowand above 425 microns were as follows:

PVA Layer Mass Yield: 88.26%   <425 microns 89% >425 microns (overs) 11%The particle size distribution is shown in Table 8.

TABLE 8 Particle Size Analysis for Enzyme Granules Produced in Example7.3 Amount of Particle size (μm) particles (%) Over 355 13.8 300-35512.4 250-300 36.8 212-250 26.3 180-212 9.7 Under 180 1.1

Example 8 Coatings on Small Granules to Reduce Dust

Small granules without protective coatings generate a significant amountof dust during pneumatic transport and filling operations, both in theenzyme granule manufacturing plant and at the customer's manufacturingplant. Dust can be both a hygienic problem and a manufacturing problem,so it must be minimized as much as possible. A small enzyme granule withthe formulation listed below was manufactured at a 3,000 kg scale, andgenerated a significant amount of Heubach dust. The Heubach dust test isdescribed, for example, in U.S. Pat. Nos. 5,324,649, 5,879,920, and7,108,821, and in Becker et al. (1997) “Formulation of DetergentEnzymes” in Enzymes in Detergency, Van Ee, J. H., Misser, O., and Baas,E., eds. Marcel Dekker, New York, pp. 299-325.

Raw Material Uncoated Granule Sodium Sulfate Seed 61.5% Enzyme solids24.6% Polyvinyl alcohol 0.5% Repel-o-tex SRP6 3.4% Sodium Sulfate Layer10.0% Total 100.0%

The Heubach dust level on the uncoated small granules shown above was476 mg/pad and it is preferable to have granules with dust levels under50 mg/pd for manufacturing.

Neodol Coating

A coating of 2% Neodol 23-6.5-T was sprayed onto the uncoated granulesdescribed above from a 10% aqueous solution using the following sprayparameters in a fluid bed spray coater:

Neodol Spray Parameters

Granule Charge 1395 grams Feed Rate 15-16 grams/minute AtomizationPressure 40 psi Inlet Temperature 90° C. Outlet Temperature 40-42° C.Airflow 52-54 cfm

The particle size distribution is shown in Table 9.

TABLE 9 Particle Size Analysis for Enzyme Granules Produced in Example 8(Neodol Coating) Amount of Particle size (μm) particles (%) Over 355 0.0300-355 21.6 250-300 68.0 212-250 9.6 150-212 0.5 Under 150 0.3

In the Neodol coated granules, Heubach dust was significantly reduced toa value of 55 mg/pad.

HPMC/PEG Coating

An 8% coating of a mixture of 90% Methocel E-15 HPMC (hydroxypropylmethyl cellulose, Dow Corning) A-15 and 10% polyethylene glycol (PEG)600 dissolved at a 5% solids level in water was sprayed onto uncoatedgranules using the spray parameters shown below:

Granule Charge 1395 grams Feed Rate 9-11 grams/minute AtomizationPressure 46 psi Inlet Temperature 94° C. Outlet Temperature 52-57° C.Airflow 50 cfm

The particle size distribution is shown in Table 10.

TABLE 10 Particle Size Analysis for Enzyme Granules Produced in Example8 (HPMC/PEG Coating) Amount of Particle size (μm) particles (%) Over 3551.4 300-355 32.8 250-300 61.2 212-250 3.5 180-212 0.4 Under 180 0.8

In the HPMC/PEG coated granules, Heubach dust was reduced to a level of20 mg/pad.

Talc/PVA/Neodol Coating

A 10% coating of a mixture of 50% Talc, 40% PVA, and 10% Neodol 23-6.5-Tdissolved in water at a 10% solids level was sprayed onto uncoatedgranules using the same spray parameters as described above for theHPMC/PEG coating. The particle size distribution is shown in Table 11.

TABLE 11 Particle Size Analysis for Enzyme Granules Produced in Example8 (Talc/PVA/Neodol Coating) Amount of Particle size (μm) particles (%)Over 355 2.2 300-355 35.4 250-300 58.5 212-250 3.3 180-212 0.3 Under 1800.3

In the talc/PVA/Neodol coated granules, Heubach dust was reduced to alevel of 16 mg/pad.

When this material was then coated with an additional 2% Neodol from a10% solution using the spray parameters described above for the Neodolcoating, the Heubach dust was further reduced to a level of 4 mg/pad.

Example 9

Enzyme-containing granules were prepared in a fluid bed spray coaterwith a barrier layer and an outer coating layer in a continuous processwithout removal of the granules from the coater between addition ofcoating layers.

152 kg of sodium sulfate crystals (from Hanhua Grade C), with a sizerange of 150 μm to 250 μm, was loaded into a pilot fluid bed coater andfluidized. 453 kg of neutral cellulase (19,295 U/g), 45 kg Repel-o-Tex20% suspension, 7.1 kg sucrose, and 4.7 kg wheat starch was spray-coatedonto the sodium sulfate crystals. 34 kg sodium sulfate solution (25% inwater) was then sprayed onto the enzyme layer. An outer coating was thenapplied by spraying 33 kg of PVA:talc:Lutensol TO 65 (4:5:1, 25%solution in water).

The spray coating parameters were as follows:

Warm-up:

Inlet air temperature 68° C. Fluidization air flow 1125 Nm³/hAtomization air pressure 4.0 bar

Enzyme Solution Spray Coating:

Solution spray rate 18.0 l/h for 20 minutes, then increased to 45 l/hover 450 minutes, then maintained at 42 l/h for remainder of run Bedtemperature 48° C. Fluidization air flow 1125 Nm³/h over 420 minutesAtomization air pressure 4.0-5.5 bar, increased over 450 minutes

Sulfate Solution Spray Coating:

Solution spray rate 36 l/h, then increased to 51 l/h over 30 minutes,then maintained at 51 l/h for remainder of run Bed temperature 50° C.Fluidization air flow 1170 Nm³/h Atomization air pressure 3.5-3.8 bar

Outer Coating:

Solution spray rate 27 l/h, then decreased to 21 l/h over 75 min- utes,then kept at 21 l/h for remainder of run Bed temperature 58° C.Fluidization air flow 1170 Nm³/h Atomization air pressure 5.5 bar

197 kg of product was harvested through a 425 μm screen. The particlesize distribution is shown in Table 12.

TABLE 12 Particle Size Analysis for Enzyme Granules Produced in Example9 Amount of Particle size (μm) particles (%) Over 355 0.7 300-355 15250-300 59 212-250 24 180-212 1.8 Under 150 0

Although the foregoing invention has been described in some detail byway of illustration and examples for purposes of clarity ofunderstanding, it will be apparent to those skilled in the art thatcertain changes and modifications may be practiced without departingfrom the spirit and scope of the invention. Therefore, the descriptionshould not be construed as limiting the scope of the invention.

All publications, patents, and patent applications cited herein arehereby incorporated by reference in their entireties for all purposesand to the same extent as if each individual publication, patent, orpatent application were specifically and individually indicated to be soincorporated by reference.

We claim:
 1. A population of enzyme-containing granules, wherein atleast about 95% of said granules comprise a single core and anenzyme-containing layer coated over said core, wherein said coreconsists of one or more inorganic salts, and wherein at least about 80%of said granules comprise a diameter of about 150 to about 355 microns.2. A population of granules according to claim 1, wherein said coreconsists of sodium sulfate.
 3. A population of granules according toclaim 2, wherein at least about 80% of said sodium sulfate corescomprise a diameter of about 100 to about 250 microns.
 4. A populationof granules according to claim 1, wherein the enzyme-containing layerfurther comprises at least one of a polymer, a sugar, a starch, or asurfactant.
 5. A population of granules according to claim 1, furthercomprising a layer comprising a barrier salt coated over saidenzyme-containing layer.
 6. A population of granules according to claim5, wherein the barrier salt layer comprises sodium sulfate.
 7. Apopulation of granules according to claim 5, wherein the barrier saltlayer comprises a mixture of two or more salts.
 8. A population ofgranules according to claim 7, wherein said mixture of two or more saltsconsists of sodium sulfate and magnesium sulfate.
 9. A population ofgranules according to claim 8, wherein said sodium sulfate and magnesiumsulfate are present in said barrier salt layer at a ratio of about 30:70to about 70:30 by weight of the barrier layer.
 10. A population ofgranules according to claim 5, further comprising an outer coating layercomprising a polymer coated over said barrier salt layer.
 11. Apopulation of granules according to claim 10, wherein said polymer is apolyvinyl alcohol.
 12. A population of granules according to claim 5,further comprising an outer coating layer comprising a pigment coatedover said barrier salt later.
 13. A population of granules according toclaim 10, wherein said outer coating layer further comprises a pigment.14. A population of granules according to claim 1, wherein said corecomprises a bulk density greater than about 1.2 g/ml.
 15. A detergentcomprising a population of granules according to claim
 1. 16. A textileprocessing composition comprising a population of granules according toclaim
 1. 17. An animal feed composition comprising a population ofgranules according to claim
 1. 18. A method of making enzyme-containinggranules, comprising coating an enzyme-containing layer onto cores in afluidized bed spray coater, wherein at least about 95% of said granulescomprise a single core, wherein said cores consist of one or moreinorganic salts, wherein said cores are pre-sieved to a particledispersity index of about 2.0 or less, and wherein at least about 80% ofsaid granules comprise a diameter of about 150 to about 355 microns. 19.A method according to claim 18, wherein said cores consist of sodiumsulfate.
 20. A method according to claim 19, wherein at least about 80%of said sodium sulfate cores comprise a diameter of about 100 microns toabout 250 microns.
 21. A method according to claim 20, wherein saidsodium sulfate cores comprise a bulk density greater than about 1.2g/ml.
 22. A method according to claim 18, further comprising coating alayer comprising a barrier salt over said enzyine-containing layer,wherein the granules are not removed from the fluidized bed spray coaterprior to addition of the barrier salt layer.
 23. A method according toclaim 22, wherein said barrier salt layer comprises sodium sulfate. 24.A method according to claim 22, wherein the barrier salt layer comprisesa mixture of two or more salts.
 25. A method according to claim 24,wherein said mixture of two or more salts consists of sodium sulfate andmagnesium sulfate.
 26. A method according to claim 25, wherein saidsodium sulfate and magnesium sulfate are present in said barrier saltlayer at a ratio of about 30:70 to about 70:30 by weight of the barrierlayer.
 27. A method according to claim 22, further comprising coating anouter coating layer comprising a polymer over said barrier salt layer,wherein the granules are not removed from the fluidized bed spray coaterprior to addition of the outer coating layer.
 28. A method according toclaim 27, wherein said polymer is a polyvinyl alcohol.
 29. A methodaccording to claim 22, further comprising coating an outer coating layercomprising a pigment over said barrier salt later, wherein the granulesare not removed from the fluidized bed spray coater prior to addition ofthe outer coating layer.
 30. A method according to claim 27, whereinsaid outer coating layer further comprises a pigment.